Methods for pretreatment and processing of biomass

• US 8,262,853 B2
• Filed: 09/05/2007
• Issued: 09/11/2012
• Est. Priority Date: 11/01/2002
• Status: Expired due to Fees

• Current Assignee: Texas A&M University System
• Original Assignee: Texas A&M University System
• Inventors: Holtzapple, Mark Thomas, Davison, Richard Read, Lowery, Lee Leon Jr., Granda, Cesar Benigno
• Primary Examiner(s): CALANDRA, ANTHONY J
• Application Number:
  US11/850,497
• Publication Number:
  US 20080121359A1
• Time in Patent Office: 1,833 Days
• Field of Search: 162/90, 162/96, 162/97, 162/41, 162/57
• US Class Current: 162/41
• CPC Class Codes: C05F 17/20 using specific microorganisms or substances, e.g. enzymes, for activating or stimulating the treatment use of invertebrates C05F17/05
• CPC Class Codes: C05F 17/986 the other material being liquid
• CPC Class Codes: C05F 5/002 Solid waste from mechanical processing of material, e.g. seed coats, olive pits, almond shells, fruit residue, rice hulls
• CPC Class Codes: C05F 9/04 Biological compost
• CPC Class Codes: C12P 1/00 Preparation of compounds or compositions, not provided for in groups C12P3/00 - C12P39/00, by using microorganisms or enzymes
• CPC Class Codes: D21C 3/02 with inorganic bases or alkaline reacting compounds, e.g. sulfate processes
• CPC Class Codes: D21C 3/026 in presence of O2, e.g. air
• CPC Class Codes: D21C 5/00 Other processes for obtaining cellulose, e.g. cooking cotton linters obtaining fibres for spinning D01C; Processes characterised by the choice of cellulose-containing starting materials
• CPC Class Codes: D21C 5/005 Treatment of cellulose-containing material with microorganisms or enzymes
• CPC Class Codes: D21H 11/12 Pulp from non-woody plants or crops, e.g. cotton, flax, straw, bagasse
• CPC Class Codes: Y02A 40/20 Fertilizers of biological origin, e.g. guano or fertilizers made from animal corpses
• CPC Class Codes: Y02P 20/145 the feedstock being materials of biological origin
• CPC Class Codes: Y02W 30/40 Bio-organic fraction processing; Production of fertilisers from the organic fraction of waste or refuse

Abstract

According to one embodiment of the invention, a system for processing biomass includes a water-impermeable bottom liner, a gravel layer supported by the bottom liner, a drain pipe disposed within the gravel layer, a biomass input device operable to deliver biomass over the gravel layer to form a biomass pile, a lime input device operable to deliver lime to the biomass for pretreating the biomass, a distribution pipe elevated above the gravel layer, and a pump operable to circulate water through the biomass pile by delivering water to the distribution pipe and receiving water from the drain pipe after it has traveled through the biomass pile.

According to another embodiment, a method for biomass pretreatment with alkali, conducted at ambient pressure for approximately 4-16 weeks at temperatures ranging from approximately 25° C. to 95° C. Biomass may be lignocellulosic biomass and may be rendered suitable for enzymatic digestion or pulp production.

Claims

1. A method of biomass pretreatment comprising:

(a) adding an alkali to biomass with lignin content to produce a mixture;

(b) maintaining the mixture at a temperature between approximately 25°

C. and 100°

C. at ambient pressure;

(c) circulating water intermittently through the mixture during step (b);

(d) fermenting the biomass; and

(e) collecting carboxylate salts from the mixture.

2. The method of claim 1, further comprising maintaining the mixture for a time period of at least approximately 4 weeks.

3. The method of claim 1, further comprising maintaining the mixture for a time period of between approximately 4 and 16 weeks.

4. The method of claim 1, further comprising selecting the duration of step (b) based on the temperature in step (b).

5. The method of claim 1, wherein the biomass comprises lignocellulosic biomass.

6. The method of claim 1, wherein the biomass comprises agricultural waste.

7. The method of claim 1, wherein the biomass is selected from the group consisting of:

bagasse, corn stover and combinations thereof.

8. The method of claim 1, further comprising circulating oxygen enriched air or pure oxygen through the mixture during step (b).

9. The method of claim 1, wherein the alkali comprises lime.

10. The method of claim 1, wherein the alkali comprises calcium oxide.

11. The method of claim 9, further comprising adding approximately 0.5 grams of lime per gram of biomass to produce the mixture.

12. The method of claim 9, further comprising adding approximately 0.1 to 0.5 grams of lime per gram of biomass to produce the mixture.

13. The method of claim 9, further comprising adding lime to the biomass in an amount between approximately 10% and 30% of biomass by weight.

14. The method of claim 1, further comprising adding calcium carbonate to the mixture.

15. The method of claim 1, further comprising maintaining the mixture at a temperature between approximately 25°

C. and 90°

C.

16. The method of claim 1, further comprising maintaining the mixture at a temperature between approximately 25°

C. and 57°

C.

17. The method of claim 1, further comprising selecting the temperature in step (b) based on the partial pressure of water at the selected temperature.

18. The method of claim 1, further comprising increasing the enzyme digestibility of the biomass.

19. The method of claim 1, further comprising producing pulp.

20. The method of claim 19, further comprising producing pulp suitable for paper or cardboard production.

21. The method of claim 1, further comprising reducing the lignin content of the biomass.

22. The method of claim 21, further comprising reducing lignin content by at least approximately 98%.

23. The method of claim 21, further comprising reducing lignin content by at least approximately 90%.

24. The method of claim 21, further comprising reducing lignin content by at least approximately 29%.

25. The method of claim 21, further comprising reducing lignin content by at least approximately 40%.

26. The method of claim 21, further comprising reducing lignin content by at least approximately 67%.

27. The method of claim 21, further comprising reducing lignin content by alkaline oxidation.

28. The method of claim 1, further comprising adding an inoculum to the mixture.

29. The method of claim 1, wherein maintaining the mixture occurs at ambient pressure, and wherein the temperature is between 25°

C. and 95°

C.

30. A method for producing enzymatically digestible biomass comprising:

(a) adding lime to biomass with lignin content to produce a mixture;

(b) maintaining the mixture at a temperature between approximately 25°

C. and 55°

C. at ambient pressure for a time period of at least approximately 4 to 16 weeks;

(c) circulating water intermittently through the mixture during step (b);

(d) fermenting the biomass; and

(e) collecting carboxylate salts from the mixture.

31. The method of claim 30, further comprising circulating air or oxygen enriched air or pure oxygen through the mixture during step (b).

32. The method of claim 30, further comprising reducing the lignin content of the biomass by at least approximately 67%.

33. The method of claim 30, further comprising reducing the lignin content of the biomass by at least approximately 32%.

34. A method for producing pulp comprising:

(a) adding lime to biomass with lignin content to produce a mixture;

(b) maintaining the mixture at a temperature between approximately 45°

C. and 55°

C. at ambient pressure for a time period of approximately 10 weeks;

(c) circulating water intermittently through the mixture during step (b);

(d) fermenting the biomass; and

(e) collecting carboxylate salts from the mixture.

35. The method of claim 34, further comprising circulating air or oxygen enriched air through the mixture during step (b).

36. The method of claim 34, further comprising reducing the lignin content of the biomass by at least approximately 90%.

37. The method of claim 34, further comprising reducing the lignin content of the biomass by at least approximately 40%.

38. The method of claim 34, further comprising producing paper or cardboard from the biomass.